Jamel Gharbi, a Socialist member of the Pays de la Loire regional council, was on holiday in the northern Tunisian city of Bizerte on 16 August when he was confronted by dozens of men who identified themselves as fundamentalist Muslim Salafists.
The 62-year-old, who was born in the city, says the group criticised what his wife and 12-year-old daughter were wearing before beating him with batons and clubs.
Gharbi says the women “were not wearing anything shocking”.
Fabius has condemned the attack as “unacceptable”.
Agriculture minister Stéphane Le Foll went further, telling the French television news channel ITele, “If this is democratic transition, then Tunisian leaders have some serious questions to answer.”
Gharbi and his family flew back to France immediately after the incident.